I first saw Yahoo’s 13 Simple Rules for Speeding Up Your Web Site referenced in a post on Rich Skrenta’s blog in May. It looks like there were originally 14 rules; one must have fallen off the list somewhere along the way.
Make Fewer HTTP Requests
Use a Content Delivery Network
Add an Expires Header
Gzip Components
Put CSS at the Top
Move Scripts to the Bottom
Avoid CSS Expressions
Make JavaScript and CSS External
Reduce DNS Lookups
Minify JavaScript
Avoid Redirects
Remove Duplicate Scripts
Configure ETags
via Coding Horror: YSlow: Yahoo’s Problems Are Not Your Problems.
Giancarlo Angulo's Blog